What is croup in children?

Croup is a common infection in children. It causes swelling in the upper part of the airway in the neck. It causes breathing problems. The illness is seen more often in the winter.

What causes croup in a child?

A virus is the most common cause of croup. But the illness may also be caused by bacteria, allergies, or reflux from the stomach. Viruses that are known to cause croup are:

  • Parainfluenza virus
  • Respiratory syncytial virus (RSV)
  • Influenza virus (flu)
  • Adenovirus
  • Enteroviruses

Croup is spread through direct contact with an infected person or his or her body fluids. The infection starts in the nose and throat and moves into the lungs. Swelling affects the area around the voice box (larynx) and into the windpipe (trachea).

Which children are at risk for croup?

Younger children are more affected by croup because their airways are smaller. A small amount of swelling can make it very hard for a baby or young child to breathe. Croup is most often seen in children 3 months to 5 years old. The peak time for croup to occur is 2 years old.

What are the symptoms of croup in a child?

The symptoms of croup are not always the same. As the illness moves from the nose to the lungs, the symptoms can change. They may include:

  • A runny nose, a stuffy nose, and slight cough
  • A cough that turns into a “seal’s bark”
  • Losing his or her voice (laryngitis)
  • Fever
  • A high-pitched “creaking” or whistling sound when breathing in (stridor)

These symptoms are often worse at night and may wake your child from sleep. They may also seem to get better in the morning but get worse as the day goes on. Most children feel better in 3 to 7 days.

The symptoms of croup can be mistaken for other health problems. Make sure your child sees his or her healthcare provider for a diagnosis.

Use our croup symptom checker.

How is croup diagnosed in a child?

Your child’s healthcare provider can diagnose croup with a health history and physical exam. Your child may need tests if the provider thinks he or she may have other illnesses. These tests include:

  • Neck or chest X-rays
  • Blood tests 

How is croup treated in a child?

Treatment will depend on your child’s symptoms, age, and general health. It will also depend on how severe the condition is.

In severe cases of croup, or if your child is not breathing well, your child may need to go to the hospital. You can manage most milder cases at home. But it can sometimes be hard to tell if your child needs to go to the hospital because the illness changes. Your child may seem better at one moment, and then get worse the next. Your child’s healthcare provider may order the following medicines to help ease symptoms:

  • Inhaled medicines. These are used if your child is having a lot of trouble breathing. Inhaled treatments may be used to ease the stridor and make it easier to breathe.
  • Steroids (injected or oral). An injectable steroid is often given if the child can’t take steroids by mouth. This medicine can help prevent the illness from getting worse.
  • Other medicines. Your healthcare provider may prescribe other medicines if he or she feels your child’s croup is from allergies or reflux. He or she may also recommend acetaminophen or ibuprofen for a fever or discomfort. Antibiotics are not useful if the illness is caused by a virus.

For a milder case, these methods may help at home:

  • Make sure your child rests and drinks plenty of f fluids.
  • Don’t smoke in the home. Smoke can make your child’s cough worse.
  • Keep your child’s head raised. Prop an older child up in bed with extra pillows. Never use pillows with babies younger than 12 months.
  • Sleep in the same room as your child to help your child right away if he or she starts to have trouble breathing.
  • Stay calm. If your child sees that you are frightened, it will increase his or her anxiety and trouble breathing.
  • Comfort your child. Sing your child’s favorite bedtime song or offer a favorite toy.

Inhaling steam or cool night air may also help with breathing. You may want to try:

  • Putting a humidifier in your child’s room.
  • Putting a warm, wet washcloth over your child’s nose and mouth as he or she breathes.
  • Creating a steam room in your bathroom. Turn on the hot water in your bathroom shower. Keep the door closed so the room gets steamy. Sit with your child in the steam for 15 to 20 minutes. Don't leave your child alone.
  • If your child wakes up at night, try bundling him or her and go outside to breathe in the cool night air.

How can I help prevent croup in my child?

You can help prevent the spread of croup with these tips:

  • Wash your hands often. Teach your child how to properly wash his or her hands.
  • Stop your child from sharing cups and other dishware.
  • Keep your child at home until he or she is better.

When should I call my child’s healthcare provider?

Call 911 right away if your child:

  • Makes a whistling sound (stridor) that becomes louder with each breath
  • Has stridor when resting
  • Has a hard time swallowing his or her saliva, or drools
  • Has increased trouble breathing
  • Has a blue or dusky color around the fingernails, mouth, or nose
  • Struggles to catch his or her breath
  • Can't speak or make sounds

Call your child’s healthcare provider right away if your child’s symptoms get worse, or if he or she:

  • Fever (see Fever and children, below)
  • Cough or other symptoms don't get better or get worse
  • Your child doesn't get better within a week

Fever and children

Always use a digital thermometer to check your child’s temperature. Never use a mercury thermometer.

For infants and toddlers, be sure to use a rectal thermometer correctly. A rectal thermometer may accidentally poke a hole in (perforate) the rectum. It may also pass on germs from the stool. Always follow the product maker’s directions for proper use. If you don’t feel comfortable taking a rectal temperature, use another method. When you talk to your child’s healthcare provider, tell him or her which method you used to take your child’s temperature.

Here are guidelines for fever temperature. Ear temperatures aren’t accurate before 6 months of age. Don’t take an oral temperature until your child is at least 4 years old.

Infant under 3 months old:

  • Ask your child’s healthcare provider how you should take the temperature.
  • Rectal or forehead (temporal artery) temperature of 100.4°F (38°C) or higher, or as directed by the provider
  • Armpit temperature of 99°F (37.2°C) or higher, or as directed by the provider

Child age 3 to 36 months:

  • Rectal, forehead (temporal artery), or ear temperature of 102°F (38.9°C) or higher, or as directed by the provider
  • Armpit temperature of 101°F (38.3°C) or higher, or as directed by the provider

Child of any age:

  • Repeated temperature of 104°F (40°C) or higher, or as directed by the provider
  • Fever that lasts more than 24 hours in a child under 2 years old. Or a fever that lasts for 3 days in a child 2 years or older.

Key points about croup in children

  • Croup is a common infection in children. It causes swelling in the upper part of the airway in the neck.
  • Croup is most often caused by a virus.
  • Children with croup have trouble breathing because their small airways swell.
  • A barking cough, fever, runny nose, and stridor are common symptoms.
  • Most cases are mild and can be managed at home.
  • A child who has a lot of breathing problems may need to go to the hospital.
  • Proper handwashing is one way to prevent croup.

Next steps

Tips to help you get the most from a visit to your child’s healthcare provider:

  • Know the reason for the visit and what you want to happen.
  • Before your visit, write down questions you want answered.
  • At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you for your child.
  • Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are.
  • Ask if your child’s condition can be treated in other ways.
  • Know why a test or procedure is recommended and what the results could mean.
  • Know what to expect if your child does not take the medicine or have the test or procedure.
  • If your child has a follow-up appointment, write down the date, time, and purpose for that visit.
  • Know how you can contact your child’s provider after office hours. This is important if your child becomes ill and you have questions or need advice.